1. Field of the Invention
The present invention relates to a TDI image sensor architecture with a row of photodiodes or pinned photo diodes.
2. Description of Related Art
Quantum efficiencies typical of high quality photodiodes in linescan CCD image sensors, in the visible wavelengths, are on the order of 70%. However, quantum efficiencies of photogates as are typically used in TDI image sensors are on the order of 40% or even lower for red and green light, and as low as around 10% for blue light. Thus, under uniform illumination, the TDI image sensor must operate with between 2 and 7 photogate stages to accumulate the same electronic signal as its single photodiode linescan counterpart. This poses significant constraints of object-imager alignment and synchronization.